Many packaging bags and many closure devices for this purpose have already been proposed.
Most closure devices known for this purpose comprise two complementary profiles, for example of male/female type or of type velvet/hooks, or even complementary hook type, borne by respective support webs.
Document FR 2 628 067 especially has proposed a bag comprising two main walls comprising two complementary closure profiles borne by respective support webs fixed respectively to the walls. The fastening area of the support web on the wall is not superposed on the male profile but is offset relative to the latter to hinge the corresponding support web on the wall at the fastening area. As is described in document FR 2 628 067, the preceding arrangement prevents internal pressure on the bag from being applied to the closure profiles and tends to separate the latter. In fact, the separation of the walls of the bag (for opening the latter) results in possible pivoting of the support web at the hinge area formed by its fastening, without risk of separation of the closure profiles.
Bags responding to this arrangement have already given considerable service and make reopening of the bag difficult, so as to assure its user that its contents cannot spill out easily.
It has also been proposed in document FR 2 963 927 for the two areas fastening of the webs to be located at a distance from and on either side of the corresponding complementary profiles such that one of the hinged webs is directed towards the interior of the bag while the other hinged web is directed towards its mouth.
These bags resist even more the internal and external stresses of the walls of the bag, at which point it is proving very difficult today to open them without damaging the closure device or the walls of the bag.
But in some cases, it can prove necessary for the bag to be opened without damaging it to access its contents and being sure of being able to reclose it after opening.
Such a bag applies for example to the field of the packaging of noxious products such as dishwater tablets. In fact, it is important to be able to assure users that the bag stays closed between two uses especially to prevent children from accessing its contents, with the possibility for parents to open and reclose the bag a number of times without risking damaging it, and preferably without the successive opening and closing being too difficult.